Chewing gum composition and method of making same

ABSTRACT

The present invention is a chewing gum base composition which includes an elastomer and a resin prepared in the absence of rosin esters and terpene components which includes an elastomer component raised to a compatibilization temperature for addition of a compatibilization component. The composition includes a high melting point wax compatibilization component added under low shear mixing conditions at a temperature sufficient to masticate the elastomer for forming a substantially homogeneous mass with the resin component. The compatibilization component is capable of effectuating dissociation of the elastomer under the conditions of temperature and mixing for forming the substantially homogeneous mass. Finally, a resin component is added also under low shear mixing conditions and mildly elevated temperatures until a substantially homogenous gum base mass is formed.

This application is a continuation-in-part of Ser. No. 865,509 filed May20, 1986 which is now U.S. Pat. No. 4,876,095.

BACKGROUND OF THE INVENTION

The present invention relates to the art of chewing gum basecompositions, and, in particular, to gum base compositions which includean elastomer and a resin component prepared without the need for certainundesirable components.

Chewing gums available today generally contain a water-insoluble or baseportion and a water-soluble flavor portion which is dissipated over aperiod of time during mastication of the gum in the oral cavity. Thebase portion can include a natural or a synthetic elastomer, and,optionally, a resin component and a texturizing component for achievinga particular perceived effect by the consumer.

The present invention is particularly concerned with those gum basecompositions in which there are both an elastomeric portion as well as aresin component which can be made to be compatible in combinationwithout the need for certain undesirable ingredients heretoforegenerally considered necessary.

The elastomer component can, in accordance with the present state of theart, include synthetic elastomers, natural elastomers, or combinationsthereof. This element generally provides the insoluble cud withresiliency to recover from deformation caused during chewing. The resincomponent, which is also a polymeric material, provides the insolublecud portion of the gum with other desirable characteristics such as filmforming capabilities, and inherent strength for unbroken deformationunder chewing forces, i.e., "lay-flat" quality, etc.

In order for the overall cud containing both an elastomeric portion anda resin component to retain the desired characteristics of thecombination, the inherent cohesivity of each of the individualcomponents must be overcome or dissociated to some extent in order toopen up the structure sufficiently to be compatible for mixing. Onlywhen the two components are "opened up" sufficiently to be miscible tosome extent with each other, can a satisfactory base portion be providedfor addition of desired texturizing agents and eventually chewing gumcomposition ingredients, e.g., sugar, flavoring, etc.

Thus, in order to prepare a high-grade gum base, it is necessary toeffect compatibilization of an elastomer and the resin component whenthe two are used in combination. In the case of high molecular weightresins, this can be a particularly difficult problem, in view of theintensity of the inherent strength of the inter-molecular attractiveforces or inter-molecular interaction.

In the past, it has been generally considered necessary to include rosinesters, hydrogenated rosin esters, polymerized rosin esters andunhomogenized rosin esters, and terpene resins to compatibilize theelastomeric component with the resin component especially high molecularweight resin such as high molecular weight polyvinylacetate, e.g.,having a molecular weight of greater than about 20,000.

Although the use of these esters and ester derivatives, help tocompatibilize otherwise generally immiscible gum components, there areseveral drawbacks which would encourage one to refrain from using suchester gums. In particular, ester gums have unpleasant taste and odor andare characteristically rigid, very hard, brittle, nonchewable, andrequire significant amount of energy as well as the addition ofextensive amounts of softeners, fillers, etc., in order to achieveproper texturization. Thus, even though the gum can be pliable andelastic at the beginning of the chewing or mastication period, it canquickly become excessively pliable and sticky in the mouth, lose itselasticity, and develop an unpleasant chewing sensation. Furthermore,cracks can develop in the gum during storage which can cause shedding.

Similarly, elastomer solvents used to compatibilize elastomer componentswith resins have included terpene resins such as polymers of betapinene, and beta-pinene. Other problems are incurred by use of theterpene solvents, similar to those problems incurred by use of rosinesters and derivatives thereof.

Efforts in the past to eliminate the need for wood rosin esters andterpenes, have included polymerizing the monomer unit of a resin such asvinyl acetate and/or vinyl propionate in the presence of a hydrogenatedpetroleum resin alone or in mixture with a hydrogenated petroleum resinwith known chewing gum base additives and/or known natural resins forchewing gum bases. This is disclosed in Japanese Patent PublicDisclosure No. 49-205,10 (1974). Other efforts have included the use ofcomparatively expensive compatibilization components such as glyceroltriacetate, and acetylated monoglyceride, combinations thereof, etc. Forexample, U.S. Pat. No. 4,452,820 to D'Amelia, et al. discloses a singlephase formulated homogeneous gum base which contains a plasticizedelastomer and a plasticized resin in the absence of ester gum. In thecase of the D'Amelia, et al. '820 disclosure, a styrene butadieneelastomer is plasticized with a plasticizer selected from one of butylstearate, butyl oleate, glycerol trioleate, oleic acid, or mixturesthereof, while the resin component is plasticized with a plasticizerselected from the group consisting of glycerol triacetate, glyceroltributyrate, triethyl citrate, acetylated monoglyceride, etc. andcombinations thereof. In the case of the process disclosed in theJapanese reference, it is required to copolymerize the components, andin the case of the D'Amelia '820 disclosure, it is necessary to providea plasticizer for each of the components, one of which is a ratherexpensive plasticization component.

U.S. Pat. No. 4,525,363 to D'Amelia, et al. discloses a variety ofpolymers which plasticize both the resin and the elastomer components.The polymers are of the polymeric resin type materials and include, forexample, acrylates, acetates, butylenes and silicones. The elastomer maybe a styrene butadiene whereas the resin may be a polyvinyl acetate. TheD'Amelia, et al. '363 reference also discloses the optional inclusion ofwaxes having a relatively low melting point which may be present in anamount of from about 0% to about 18% so as to reduce the tackiness ofthe final gum composition.

U.S. Pat. No. 2,284,804 to De Angelis discloses polybutene chewing gumbase compositions which include the use of "substantial quantities ofwax at least equal to the amount of polybutene present." (Col. 2, Lines28-30). The resin component of the base disclosed, however, isindiscriminately chosen from hydrogenated synthetic and hydrogenatednatural resins and ester gums. (Col. 2, Lines 42-45.).

The use of waxes in a gum base has also been contemplated. U.S. Pat. No.2,137,746 to Wilson discloses chewing gum bases which include smallproportions of paraffin waxes having melting points in the range ofabout 160° F. to about 185° F. in combination with natural elastomers orin combination with latex elastomers and ester gums so as to improve thesmoothness of the gum formulations while retaining the other desirableproperties of the springiness and roundness of the cud. The Wilsondisclosure, however, fails to suggest a gum base having compatibilizedsynthetic elastomers.

Similarly, in U.S. Pat. No. 3,984,574 to Comollo an attempt has beenmade to reduce the need for rosin derivatives, with polyvinyl acetateand polyterpenes in order to reduce the tackiness associated with suchbases. In order to do so, Comollo requires the use of polyisobutylene incombination with polyvinyl acetate and hydrogenated or partiallyhydrogenated vegetable oils or fats in an amount of 5-50%, and filler inan amount of 5-40% in order to allegedly achieve an adhesive ornon-tacky base. The Comollo '574 disclosure requires the use ofvegetable oils and fats and mineral adjuvants as fillers to achieve thedesired result. Thus, it is an object of the present invention toprovide a gum base composition which includes both an elastomer and aresin in the absence of rosin esters.

It is a further object to provide a gum base as described above whichdoes not require the use of terpene softeners.

A further object of the present invention is to provide a gum basewithout the need for ester and terpene softeners by use of a inexpensivecompatibilization component.

Yet a further object of the present invention is to provide a gum basein which a chewing gum composition can be prepared in a continuousprocess without the requirement for aging, cooling, etc.

Other objects will become apparent to the skilled practitioner in viewof the disclosure as set forth below.

SUMMARY OF THE INVENTION

The present invention is a chewing gum base composition having anelastomer component and a resin component which can be prepared in theabsence of rosin esters and terpenes. The present chewing gum basecomposition includes an elastomer component raised to acompatibilization temperature for addition of a compatibilizationcomponent. It further includes a high melting point compatibilizationcomponent, preferably a high melting point wax which can be added underlow shear mixing conditions at a temperature sufficient to masticate theelastomer for forming a substantially homogeneous mass with the resincomponent. The compatibilization component is capable of effectingdissociation of the elastomer under these conditions of temperaturemixing for forming the substantially homogeneous mass. Finally, a resincomponent is added under low shear mixing conditions and at mildlyelevated temperatures until a substantially homogeneous gum base mass isformed.

Optionally, the gum base composition of the present invention caninclude a texturizing component having ingredients selected from thegroup consisting of softeners, fillers, emulsifiers, and combinationsthereof.

Elastomers can be those which are normally used in gum bases. Forexample, the elastomer component can be selected from the groupconsisting of styrene-butadiene copolymer, polyisobutylene,polyisoprene, isobutylene-isoprene copolymer and natural elastomers.Other elastomers compatible for use as a gum base component are includedherein.

In one preferred embodiment, the gum base composition can include afirst solid elastomer component and a cold flow elastomer componentafter said solid elastomer component has been masticated by use of saidhigh melting point compatibilization component.

Preferably the high melting point compatibilization component is a highmelting point wax wherein the melting point is from about 130° to about250° F., preferably from 160° to 215° F., and most preferably between175° and 195° F. Such waxes can include microcrystalline wax andparaffin wax.

The resin component of the gum composition of the present invention ispreferably a high molecular weight resin selected from the groupconsisting of polyvinyl acetate, polyvinyl butylester, copolymers ofvinylesters and vinylethers, polyethylene, ethylene-vinylacetatecopolymers, vinylacetate, vinylalcohol copolymers,vinylacetate-vinyl-laurate copolymers, and combinations thereof. By highmolecular weight it is meant that the resin have at least about 20,000MWU.

With regard to the texturizing component, softeners can be selected fromthe group consisting of hydrogenated vegetable or animal fats, glycerolmonostearate, lecithin, coconut oil, palm oil, fatty acids, glyceroltriacetate, and acetylated monoglyceride and combinations thereof.Furthermore with regard to the texturizing agent, there can be includeda filler component selected from the group consisting of calciumcarbonate, aluminum hydroxide, alumina, magnesium carbonate, dicalciumphosphate, talc, magnesium trisilicate, magnesium hydroxide, aluminasilicates, silica gel, organic fillers, and combinations thereof.

Preferably, the gum base composition includes elastomer component in anamount of from about 5% to 20% by weight of said base, and, morepreferably from about 7% to about 15% by weight; whereas the resincomponent is included in an amount of from about 10% to about 50% byweight based on the gum base, and is preferably included in an amount offrom about 25% to about 40% by weight. The high melting pointcompatibilization component, e.g., high melting point wax is included inan amount of from about 15% to about 55% by weight of the base, and ispreferably from about 28% to about 45% by weight. Finally, thetexturizing component is included in an amount of from about 10% toabout 35% of the base, and is preferably included in an amount of fromabout 12% to about 24% by weight.

The present invention also includes the method of preparing a gum basecomposition by heating the elastomer component to a temperature of fromabout 220° C. to about 250° C. followed by step-wise addition of thecompatibilization component, such as high melting point wax in, forexample, four increments followed by 10 minutes of mild mixing.

In a most preferred embodiment, it has been known to use a cold flowelastomer component as an additional compatibilization component suchelastomer defined as not being a solid at room temperature.

Finally, the present invention also contemplates chewing gumcompositions which includes a gum base composition prepared inaccordance with the formula and in accordance with the method set forththerein.

As a result of the present invention a high quality gum base can beprepared for use in nearly all types of gum compositions without theneed for inclusion of wood rosin esters and derivatives thereofincluding terpene components. Thus, as a consequence, characteristicsand features of such ester components which detract from the quality ofa chewing gum base and composition made therefrom are eliminated.

It is also possible as result of the present invention to continue toprepare a chewing gum composition continuously from the preparation ofthe chewing gum base by continued mixing without the requirement ofintermittent cooling, aging or otherwise interrupting the chewing gummaking process.

For a better understanding of the present invention, together with otherand further objects, reference is made to the following description, andits scope will be pointed out in the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

In the preferred embodiments of the present invention, it has been foundthat a gum base can contain any of the preferred elastomer components incombination with a resin component to form a single phase homogeneousbase with or without a texturizing component to render a base with goodorganoleptic properties.

In particular, the elastomer component of the gum base of the presentinvention can be selected from the synthetic elastomersstyrene-butadiene copolymer, polyisobutylene, isobutylene-isoprenecopolymer (butyl rubber), natural rubber (polyisoprene), as well asmasticatory substances of natural origin, such as rubber latex solids,chicle, crown gum, nisparo, rosidinha, jelutong, pendare, perillo, nigergutta, tunu, etc.

The resin component, on the other hand, can be selected from polyvinylbutyl ester, copolymers of vinyl esters and vinyl ethers, polyethylene,ethylene-vinyl acetate copolymers, vinyl acetate-vinyl alcoholcopolymers, vinyl acetate vinyl laurate copolymers, and in particularhigh molecular weight polyvinyl acetate, which is at least about 20,000MWU.

Since both the elastomers and the polymeric resins have an inherentlystrong intermolecular interaction, sometimes referred to as cohesiveenergy-density, which must be overcome to some extent in order toachieve compatibility, the elastomer is first treated to be opened upsufficiently to effect miscibility with the selected resin. Accordingly,it has been found that the elastomer, such as polybutyl rubber can beheated to a temperature for opening up the intermolecular structureunder conditions of low shear mixing, such as with a sigma blade at lowrevolutions, after which a high melting point compatibilizationcomponent can be added.

As mentioned before, the preferred high melting point compatibilizationcomponents include high melting waxes such as microcrystalline wax,paraffin, etc.

The compatibilizing wax should be added in increments in a step wiseaddition process, after the elastomer has been reduced to a fineparticulate consistency, such as a sandy consistency. Interestingly, ithas been found that liquid wax used in a compatibilization role at thesetemperatures and conditions do not properly affect the conditioning ofthe elastomer in order to effect miscibility with the resin component.

Thus, in one embodiment the wax component which is included in an amountof from about 15% to about 55% based on the weight of the gum base, canbe added in increments of 25% of the overall weight of the wax andsubjected to the above-described mixing conditions for periods, of, forexample, 10 minutes each.

In the most preferred embodiment, it has been found that a non-solidelastomer, such as an oligomeric butyl rubber component can be includedas one of the step-wise additions of the wax component, to achieve anoptimum elastomeric component suitable for forming into a homogeneousgum base with a resin, especially a high molecular weight resin. Whilethe reason for the increased efficiency of mixing using the oligomericelastomer is not entirely certain, it is believed that the principle oflike components dissolve like components comes into play, and that thenon-solid oligomeric component enters into the intermolecular structureto increase miscibility therewith. One particularly effectivecombination has been found to be a solid polybutyl rubber elastomer incombination with oligomeric butyl rubber cold flow material, e.g.,Vistanex (LMMH) tradename of Exxon Corporation.

In the event that the additional oligomeric elastomer is added, theremainder of the wax should be added in the increments of about 25% ofthe total wax, each addition under continued mixing and temperature. Ithas been found that a particularly effective compatibilization componentis a microcrystalline wax having a melting point of about 195° F.

Once the elastomer component in combination with the compatibilizationcomponent has reached a highly viscous, substantially single phasehomogeneous mass, the resin component can be added, also preferably instep-wise increments under continued conditions of low shear mixing andelevated temperatures. In particular it has been found that highmolecular weight polyvinyl acetate in an amount of about 30 to 45% ofthe overall weight of the gum base can be added to the masticatedelastomer in increments of about 1/3 each step and blended for aboutfive minutes during each addition.

As a result of this unique combination and method of mixing, theelastomeric and resin component come together to form a miscible singlephase homogeneous plastic mass to which a texturizing component can beeasily incorporated without undue processing effort. It is important tonote that the initial processing steps have been conducted at atemperature maintained between 220° to about 250° C., at which pointmost of the heretofore known plasticizers would vaporize and boil off.This is especially true since under the mixing conditions, thetemperature of the working plastic mass can easily attain a temperatureof about 270° C. Thus, it is important to use very high boiling pointwaxes in order to prevent loss of the compatibilization component duringmixing.

At this point, a texturizing component can optionally be added whichusually includes materials such as fillers, softeners, emulsifiers,anti-oxidants, etc. Examples of fillers suitable for use include calciumcarbonate, aluminum hydroxide, alumina, magnesium carbonate, dicalciumphosphate, talc (3MgO.4SiO₂.H₂ O), magnesium trisilicate, magnesiumhydroxide, aluminum silicates, silica gel, organic fillers andcombinations thereof, calcium carbonate being one of the preferredfillers. In the event that acid flavors and/or acid sweeteners, such asa free acid form of saccharin, acid cyclomate or aspartame are employedin a final chewing gum composition, it is preferred to employ anon-chalk filler such as talc.

Other softening agents which can be included over texturizing componentare glycerol triacetate acetylated monoglyceride, benzyl benzoate,benzyl butyrate, etc., with gylceryl triacetate being a preferredsoftener.

Other components include the use of hydrogenated or partiallyhydrogenated vegetable oils or animal fats such as soybean, cottonseed,corn, peanut, palm oil, tall oil, and lard.

Additionally, emulsifiers and anti-oxidants, such as butyl hydroxyanisolcan be added as required.

WORKING EXAMPLES OF THE INVENTION

Actual samples of the present invention have been prepared utilizing ageneral composition formula as shown below in Table I.

                  TABLE I                                                         ______________________________________                                        GENERAL FORMULA FOR GUM BASE WITHOUT ROSIN                                    ESTERS                                                                        Gum Base Ingredients                                                                            % By Weight of Gum Base                                     ______________________________________                                        Elastomer Component                                                                             7% to 15%                                                   solid elastomeric component                                                                     5% to 15%                                                   non-solid elastomer component                                                                   0% to 10%                                                   Compatibilization Component                                                                     28% to 45%                                                  Resin Component   25% to 50%                                                  Optional Texturizing Component                                                                  0% to 45%                                                   ______________________________________                                    

In order to effect proper formation of a homogeneous substantiallysingle phase gum base, it is important that the solid elastomericcomponent be heated to a compatibilization temperature before thecompatibilization component, which must be one that will not volatilizeat such high temperature, can be added and worked with the elastomer.

In particular, it has been found that in the case of the more specificformulation shown in Table II below, the elastomeric component should beheated to a temperature of from about 220° C. to about 250° C., beforestep-wise addition of a compatibilization component is commenced.

                  TABLE II                                                        ______________________________________                                        GENERAL FORMULATION FOR A SPECIFIC BASE                                       COMPOSITION                                                                   Gum Base Ingredient                                                                              % By Weight Of Gum Base                                    ______________________________________                                        Elastomer Component                                                                               4% to 10%                                                 Solid Butyl Rubber                                                            Optional Non-Solid 0% to 6%                                                   Butyl Oligomeric Butyl Rubber                                                 Component                                                                     Resin Component, High Molecular                                                                  15% to 45%                                                 Weight Polyvinyl Acetate                                                      Compatibilization Component                                                                      15% to 32%                                                 High Melting Point Wax                                                        Texturizing Component                                                         Vegetable Oil      12% to 25%                                                 Softener           2% to 6%                                                   Filler              5% to 14%                                                 Emulsifier/Anti-oxidant                                                                          --                                                         ______________________________________                                    

In the case of the above formulation, it has been found that the solidbutyl rubber can be raised to the desired temperature at which pointportions of the high melting point wax can be added under mild mixingconditions with for example, a sigma blade mixer at low rpm's untildifferent levels of consistency are attained after each addition.

Optionally, the non-solid butyl rubber oligomeric material can be addedwhich has been found to particularly enhance the preparation of theelastomeric component. Once an essentially homogeneous plastic mass hasbeen attained, the resin component can then be added also in a step-wisemanner followed by addition of the texturizing component in incrementsof, for example, the filler material, followed by a vegetable oil, andsofteners such as triacetin and finally the emulsifiers and/oranti-oxidants. In general, it has been found that once the elastomericcomponent has been heated to the desired temperature for mastication,the additional ingredients can be added in by order of decreasingmelting points.

This can be compared to the conventional gum base which requiresmasterbatching the rubber at 150° to 180° C. during which time the rosinesters should be used to solubilize the rubber to the degree necessaryto incorporate lower melting point components. Additionally, as aunexpected attribute of the gum base formed in accordance with thepresent invention, the process for making the overall composition can becontinued without the need for cooling or otherwise aging the basematerial. Thus, a continuous process could be employed in order toeffect formulation of a chewing gum composition.

SPECIFIC EXAMPLES OF THE INVENTION EXAMPLE 1

A specific chewing gum base formulation was prepared in accordance withthe composition set forth in Table III.

                  TABLE III                                                       ______________________________________                                        Gum Base Ingredient                                                                             % By Weight Of Gum Base                                     ______________________________________                                        Elastomeric Component                                                                            5.70                                                       Solid Butyl Rubber                                                            Non-solid Butyl Rubber                                                                           3.40                                                       Oligomeric Material                                                           Compatibilization Component                                                                     22.00                                                       High Melting Point Micro-                                                     crystalline Wax                                                               Resin Component   35.00                                                       High Molecular Weight Poly-                                                   vinyl Acetate (greater than                                                   20,000 MWU)                                                                   Texturizing Component                                                         Hard Palm Oil     17.33                                                       Calcium Carbonate 10.00                                                       Triacetin          3.90                                                       Butyl Hydroxyanisol                                                                              2.67                                                                         100.00                                                      ______________________________________                                    

The solid butyl rubber material was heated under pressure ofapproximately 30 pounds per square inch to a temperature of 220° C. to250° C. and stirred with a sigma blade stirrer until the materialreached a fine particulate consistency, e.g., sandy consistency. At thispoint approximately 1/4 of the compatibilization component (high meltingpoint microcrystalline wax) was added and stirred for 10 minutes afterwhich a second portion of the wax was added and stirred. This procedurecould be continued until all the wax material or compatibilizationmaterial is added, but it has been found that a particularly effectivecomposition method includes the addition of a non-solid butyl rubbermaterial under the low shear mixing conditions. This addition of thenon-solid material such as an oligomeric butyl rubber material can beincluded as one of the steps for masticating the elastomeric material.In the present example, after two portions of about 25% each of the highmelting point wax were added, the non-solid butyl rubber was added andstirred for about 15 minutes followed by addition of two more portionsof about 25% each of the melting point wax, followed by 10 minutes ofstirring per each addition. At this point the elastomeric material hadachieved a substantially single homogeneous plastic mass, to which theresin, high molecular weight polyvinyl acetate, was added in incrementsof 1/3 each followed by stirring about five minutes after eachincremental addition. Upon addition of the high molecular weightpolyvinyl acetate the temperature of the overall mass is still at about220° C., which, under the work generated by the sigma blade mixtures,can achieve temperatures in the range of about 270° C. Thus, as a resultof the present invention it would be impossible to use softeners knownin the art, such as glycerol triacetate, having a boiling temperature ofabout 258° C., since it would flash off under the mixing conditions ofthe present invention.

Once the elastomeric and resin gum base components have beencompatibilized, a texturizing component which includes traditional gumbase ingredients can then be added. In the present example, calciumcarbonate was added and stirred for about 10 minutes followed bystep-wise additions of the palm oil in increments of 1/3 portions of theoverall amount followed by stirring for about five minutes for eachportion. Finally, glycerol triacetate was added with five minutes ofstirring followed by the addition of butyl hydroxyanisol and stirring ofthe overall composition for 20 minutes under a reduced temperature. Theresulting gum base was a substantially single phase homogeneous masswhich was easily composited into different commercial type chewing gumcompositions.

EXAMPLE 2

A second chewing gum base was prepared in accordance with thecomposition shown in Table IV.

                  TABLE IV                                                        ______________________________________                                        Gum Base Ingredient                                                                             % By Weight Of Gum Base                                     ______________________________________                                        Butyl Rubber       8.90                                                       Compatibilization Component                                                                     15.00                                                       High Melting Point Micro-                                                     Crystalline Wax                                                               Resin Component   40.00                                                       High Molecular Weight Poly-                                                   vinyl Acetate (greater than                                                   20,000 MWU)                                                                   Texturizing Component                                                         Hard Palm Oil     17.33                                                       Calcium Carbonate 10.00                                                       Triacetin          6.10                                                       Butyl Hydroxyanisol                                                                              2.67                                                                         100.00                                                      ______________________________________                                    

As in the previous Example, the solid butyl rubber was heated underpressure of about 3 pounds per square inch to a temperature of fromabout 220° to about 250° C. followed by the step-wise addition of fourapproximately equal portions of a high melting point wax, each additionfollowed by 10 minutes of low shear stirring with a sigma blade mixer.Once a homogeneous plastic mass is achieved, polyvinyl acetate is addedin three portions each portion followed by about five minutes of lowshear stirring. Again, at this point a substantially single phase basematerial has been formed and to which a texturizing component whichincludes filler, vegetable oils, softeners and other ingredients can beadded. In the present Example, calcium carbonate was then added followedby 10 minutes of stirring and the palm oil was added in 1/3 increments,each increment being stirred for five minutes each. Finally, thetriacetin was added as a softener and stirred for five minutes beforeadding the butyl hydroxyanisol and overall stirring for 20 minutes. Asbefore, the gum base of the present invention was a very smooth, goodfilm-forming gum base material which can be used with eithersugar-containing or sugarless chewing gum compositions.

EXAMPLE 3

In this Example, a peppermint chewing gum containing the gum basecomposition was prepared in accordance with the present invention so asto compare the attributes of the present gum base composition with acontrol chewing gum base made in accordance with the prior art so as toinclude wood rosin esters.

Inasmuch as peppermint is one of the least stable among gum flavors, thecomparison is a good indicia of the improved shelf life stability of thegums of the present invention over those known in the art.

The ingredients of the respective chewing gums are set forth in Table V.

                  TABLE V                                                         ______________________________________                                        Ingredients      Wt. (gm)                                                     ______________________________________                                        INVENTION                                                                     Gum base without 106.0                                                        wood rosin esters                                                             Sorbitol powder  249.2                                                        Glycerin         40.0                                                         Peppermint flavor                                                                              4.8                                                          CONTROL                                                                       Regular gum base                                                              (wood rosin esters)                                                                            106.0                                                        Sorbitol powder  249.2                                                        Glycerin         40.0                                                         Peppermint flavor                                                                              4.8                                                          ______________________________________                                    

The chewing gum compositions were prepared using conventional mixingequipment. The sorbitol powder is first added to the mixing kettle whichis mixed for approximately three (3) minutes in order to break up lumps.The gum base, heated to approximately 95° C. so as to be in a moltenstate, is added to the sorbitol powder and while mixing, the glycerincomponent is added. The composite was then mixed for an additional three(3) minutes. Finally, the peppermint flavorant oil is added and mixedfor a final three minute period. The finished gum product was rolled andscored.

Both the control gum and that of the present invention were stored at45° C. for three (3) weeks which would be approximately equivalent to ashelf storage of two (2) years at room temperature (approximately 20°C.).

The two gums were then subjected to a blind organoleptic surveyevaluation by sixty (60) sensory expert panelists. Each individual wasasked to subjectively rate the quality of each gum on a scale of 1 to 9;9.0 being most liked and 1.0 being least liked. Three categories werejudged: overall preference, flavor and texture. The results weretabulated and average mean values derived and set forth in Table VI.

                  TABLE VI                                                        ______________________________________                                                  Overall    Flavor  Texture                                                    Preference Quality Quality                                          ______________________________________                                        Invention   7.5          6.4     6.1                                          (without rosins)                                                              Control     4.3          3.8     5.7                                          (with rosins)                                                                 ______________________________________                                    

Referring to Table VI, the results of the organoleptic surveydemonstrate the superiority of the present invention in all categoriestested. Gum made in accordance with the present invention was given anoverall preference rating of almost 75% higher (7.5 to 4.3), than thecontrol gum made in accordance with the prior art. Further, the flavorquality rating of the gum made in accordance with the present inventionwas 68% higher, (6.4 to 3.8) than the control while the texture qualityrating of the gum made in accordance with the present invention was 7%higher than the control. These results demonstrate a significantimprovement in chewing gum product using the inventive chewing gum base.

The chewing gum of the present invention and the control formulationwere also subjected to a thirty minute peppermint chew out evaluation.This test compares the percent by weight of the peppermint flavorcontained in a gum sample to the amount of peppermint flavor whichremains in the bolus after a thirty minute mastication period. Theresults are set forth in Table VII.

                  TABLE VII                                                       ______________________________________                                                   Peppermint                                                                              Peppermint    Percent                                               In Gum    Remaining in Bolus                                                                          Flavor                                     Formulation                                                                              % By Wt   % by Wt       Chew Out                                   ______________________________________                                        Invention  1.195     0.854         28.5                                       (without rosins                                                               in gum base)                                                                  Control    1.182     1.090          7.8                                       (with rosins in                                                               gum base)                                                                     ______________________________________                                    

The gum composition made in accordance with the novel gum base of thepresent invention is capable of retaining in the end product a higherpercent by weight of the desired flavor. As Table VII shows, forexample, by excluding rosins from the gum base, an approximately 1.1%(1.1.95-1.182=0.013÷1.182×100%) greater amount of peppermint wasincorporated in the final gum product. Given the extreme potency of theflavor oils and small amounts used in gum products, a 1.0% percentincrease in retained flavor is quite meaningful in terms of finalproduct flavor release properties.

Referring to Table VII, an even greater enhancement in product qualityis demonstrated. In particular, these results show that the gum samplemade in accordance with the present invention provided a hefty 28.5%chew out of the peppermint flavor (1.195-0.854=0.341÷1.195×100%). Thecontrol gum, on the other hand, was only able to provide a meager 7.8%chew-out of the peppermint flavor (1.182-1.090=0.092÷1.182×100%). Theresults of a chew-out evaluation demonstrate an almost four-foldincrease in peppermint flavor released by the chewing gum of the presentinvention when compared o the prior art as represented by the control.

Furthermore, the presence of wood rosin esters in gum subjects theflavors to interactions therewith, thereby prohibiting the freemigration of flavors and of the gum during mastication. The eliminationof the wood rosin esters eliminates this undesirable interaction andpermits the flavor to be exuded during chewing. The results of the abovetests clearly demonstrate the efficacy of the present invention inachieving this phenomenon.

The superior results achieved by the present invention convincingly showthat it is now possible to compatibilize an elastomer and a resin in achewing gum base composition without including undesirable andheretofore generally considered necessary ingredients. Also the chewinggums made in accordance with the gum bases of the present invention arepreferable and offer superior organoleptic properties.

The ineluctable conclusion is that chewing gums made in accordance withthe present invention exhibit accentuated flavor delivery throughout thechewing or mastication period. By eliminating the need for wood rosinesters and terpenes, the present invention allows for thecompatibilization of both the elastomer and resin within the gum basewhile at the same time providing a chewing gum capable of providing asignificantly increased amount of flavor released.

Upon review of the above description and specific Examples of thepresent invention, one skilled in the art will readily understand itsapplicability to other gum base compositions which normally require theuse of wood rosin esters in general, and, in particular, ester gums aswell as terpenes.

This invention may be embodied in other forms or carried out in otherways without departing from the spirit or essential characteristicsthereof. The present disclosure is therefore to be considered as in allrespects illustrative and not restrictive, the scope of the inventionbeing indicated by the appended claims, and all changes which comewithin the meaning and range of the equivalency are intended to beembraced therein.

I claim:
 1. A chewing gum base composition being substantially devoid ofrosin esters and terpene components comprising:(a) an elastomercomponent selected from the group consisting of synthetic and naturalrubber polymers; and mixtures thereof (b) a high melting point waxcompatibilization component; and (c) a high molecular weight polymericresin component.
 2. The chewing gum base of claim 1 which furthercomprises a texturizing component selected from the group consisting ofsofteners, fillers, emulsifiers, and combinations thereof.
 3. Thechewing gum base of claim 1 wherein said elastomer is selected from thegroup consisting of styrene-butadiene copolymer, polyisobutylene,polyisoprene, isobutylene-isoprene copolymer and natural elastomers andcombinations thereof.
 4. The chewing gum base of claim 1 wherein saidelastomer includes a first solid elastomer component, and a cold flowelastomer component added after said solid elastomer component has beenmasticated by use of said high melting point compatibilizationcomponent.
 5. The chewing gum base of claim 4 wherein said high meltingpoint wax is selected from the group consisting of microcrystalline wax,paraffin wax, and mixtures thereof.
 6. The chewing gum base of claim 1wherein the melting point of said high melting point compatibilizationcomponent is about 160° to about 215° F.
 7. The chewing gum base ofclaim 1 wherein the melting point of said high melting pointcompatibilization component is about 175° to about 195° F.
 8. Thechewing gum base of claim 1 wherein said polymeric resin is selectedfrom the group consisting of polyvinyl acetate, polyvinyl butylester,copolymers of vinyl esters and vinyl ethers, polyethylene,ethylene-vinyl acetate copolymers, vinyl acetate, vinyl alcoholcopolymers, vinyl acetate-vinyl laurate copolymers, and combinationsthereof.
 9. The chewing gum base of claim 8 wherein said resin is a highmolecular weight polyvinyl acetate having a molecular weight of at leastabout 20,000.
 10. The chewing gum base of claim 2 wherein said softenersare selected from the group consisting of hydrogenated vegetable oranimal fats, glycerol monostearate, lecithin, coconut oil, palm oil,fatty acids, glycerol triacetate, and acetylated monoglyceride andcombinations thereof.
 11. The chewing gum base of claim 2 wherein saidfillers are selected from the group consisting of calcium carbonate,aluminum hydroxide, alumina, magnesium carbonate, dicalcium phosphate,talc, magnesium trisilicate, magnesium hydroxide, aluminum silicates,silica gel, organic fillers, and combinations thereof.
 12. The chewinggum base of claim 2 wherein said emulsifiers are selected from the groupconsisting of glycerol monostearate, lecithin, cephalin, Tweens, Spans,and mixtures thereof.
 13. The chewing gum base of claim 1 wherein saidelastomer component is included in an amount of from about 5% to about20% by weight of said base.
 14. The chewing gum base of claim 1 whereinsaid elastomer component is included in an amount of from about 7% toabout 15%.
 15. The chewing gum base of claim 1 wherein said resincomponent is present in an amount of about 10% to about 50% by weightbased on said gum base.
 16. The chewing gum base of claim 1 wherein saidresin component is present in an amount of about 25% to about 40% byweight based on said gum base.
 17. The chewing gum base of claim 1wherein said high melting point wax compatibilization component ispresent in an amount of from about 15% to about 55% by weight of saidbase.
 18. The chewing gum base of claim 1 wherein said high meltingpoint compatibilization component is present in an amount of about 28%to about 45% by weight of said base.
 19. The chewing gum base of claim 2wherein said texturizing component is included in an amount of about 10%to about 35% by weight of said base.
 20. The chewing gum base of claim 2wherein said texturizing component is included in an amount of about 12%to about 24% by weight of said base.
 21. A chewing gum compositionprepared with a chewing gum base composition prepared in accordance withthe formula set forth in claim
 1. 22. A modified elastomer compositionuseful in a chewing gum composition and being substantially devoid ofrosin esters and terpene components comprising an elastomer componentselected from the group consisting of synthetic and natural rubberpolymers and mixtures thereof and a high melting point waxcompatibilization component having a melting point of about 130° F. (54°C.) to about 250° F. (121° C.), said wax compatibilization componentbeing capable of effecting dissociation of said elastomers underconditions of temperature and low shear mixing sufficient to form asubstantially homogenous mass.
 23. The modified elastomer component ofclaim 22 wherein said wax is selected from the group consisting ofmicrocrystalline wax, paraffin wax and mixtures thereof.